Method for carrying out an automatic braking action

ABSTRACT

The present invention relates to a method for carrying out an automatic braking action, wherein at least one quantity representative of the application of the brake pedal is determined and an automatic braking action is triggered when at least one limit value (brake pedal application limit value) of the quantity representative of the application of the brake pedal is exceeded, wherein the brake pedal application limit value is modified or the quantity representative of the brake pedal is weighted according to at least one action of the driver, in particular a detected movement of the driver&#39;s foot, prior to an application of the brake pedal of the braking action considered or prior to the considered braking action.

TECHNICAL FIELD

The present invention generally relates to vehicle brake systems andmore particularly relates to a method for carrying out an automaticbraking action.

BACKGROUND OF THE INVENTION

Systems for implementing or triggering an automatic braking action inmotor vehicles are referred to as brake assistance systems or as ‘brakeassist.’ The brake assist supports the driver in slowing down thevehicle in danger situations or emergency braking situations. It isnecessary to increase braking pressure as quickly as possible in orderto minimize the stopping distance. It is known, however, that inemergency braking situations, the average driver (normal driver) isfrequently not able, or only with a delay, to introduce the necessarymaximum braking pressure by way of the brake pedal. As soon as the brakeassist detects an emergency braking situation, the system will henceadjust the full brake pressure at the quickest possible time if thedriver reacts hesitantly.

The electronic brake assist in predominate use provides braking supporton the basis of a vacuum brake booster (booster) along with anelectrically activatable solenoid valve for ventilating the workingchamber. The prior art brake assist system analyses each brake pedalmovement the driver executes by depressing the brake pedal through thediaphragm travel of the booster. When the actuating speed derivedtherefrom reaches a threshold, the solenoid is actuated electrically andthe maximum attainable brake force boosting is adjusted thereby. Thisadditional force is withdrawn as soon as the driver no longer exertsforce to the brake pedal, which is generally detected by means of arelease switch, and when a predetermined time has lapsed since thebeginning of the active braking intervention.

Another possibility of realizing a brake assist function is advisable insystems that allow an active pressure increase by independent actuationof hydraulic components of the system, in particular an electric pump. Amaster brake cylinder (TMC) detects a panic brake pedal application ofthe driver by way of the signals of a pressure sensor. When a criticalpressure rise is exceeded, hydraulic (additional) pressure is generatedand the driver actively assisted in braking by way of actuation of thepump.

However, these brake assist systems cannot properly ascertain anemergency braking situation until the brake pedal speed exceeds a fixed,predefined threshold.

BRIEF SUMMARY OF THE INVENTION

An object of the invention is to improve the method for operating abrake assist system and to achieve an earliest possible detection of anemergency braking situation at a high rate of detection safety and arapid and effective brake pressure build-up in addition.

This object is achieved by the features of the independent patentclaims. Preferred embodiments are indicated in the dependent sub claims.

This object is achieved in that in a brake assist method, wherein atleast one quantity representative of the application or movement of thebrake pedal is determined, and an automatic braking action is triggeredwhen at least one limit value of the quantity representative of theapplication of the brake pedal (brake pedal application limit value) isexceeded. It is essential for the invention that the brake pedalapplication limit value is variable or the quantity representative ofbrake pedal application is weighted. According to the invention, thebrake pedal application limit value is varied and/or the quantityrepresentative of the brake pedal application is weighted according toan action of the driver, in particular a detected movement of thedriver's foot, prior to an application of the brake pedal of the brakingaction considered and/or prior to the proper braking action considered.

The method of the invention advantageously achieves an earliest possibleadaptation for a release criterion for an automatic full brakeapplication.

According to the invention, the situation may also be taken into accountthat prevails before the actual application of the brake pedal in thebraking action respectively considered and or before the braking actionconsidered. In particular, at least one previously performed ‘normal’braking action can be analyzed and taken into consideration. In theinvention, the brake pedal application limit value is modified and/orthe quantity representative of the brake pedal application iscorrespondingly weighted according to an individual pedal applicationperformance. The latter is detected on the basis of at least onequantity representative of the brake pedal movement, preferably at leastby way of the brake pedal speed, and this quantity was determined in atleast one, preferably several, previously (prior to the braking actionconsidered) performed normal braking actions', meaning no full brakingactions.

The brake assist will then adjust an increased or a maximum brakingpressure when the danger situations or emergency braking situations or adriver's request for a maximum deceleration and/or a critical drivingsituation were detected. The said is considered as detected when one ormore brake pedal application limit values (or brake pedal movement limitvalues) are exceeded. The modification of the limit value or a weightingof the determined brake pedal application (or brake pedal movement)according to the invention render it possible in the sense of theinvention to also consider the situation that prevailed before theapplication of the brake pedal in the release criterion for automaticfull braking.

It is arranged for in the invention that a defined brake pedal force, abrake pedal travel, a brake pedal speed and/or a brake pedalacceleration, preferably a defined brake pedal speed or a quantityderived therefrom, is used as a brake pedal application limit value. Ithas proven that these quantities of the brake pedal movement or thebrake pedal application advantageously represent relatively reliablecriteria for detecting danger situations or emergency braking situationsor a driver's request for maximum deceleration and/or a critical drivingsituation.

Preferably, a defined brake pedal speed and/or a quantity derivedtherefrom is used as a brake pedal movement limit value, and especiallya actuating speed of the brake pedal exceeding 50 mm/s, preferablyexceeding 150 mm/s, is predetermined as a brake pedal speed limit value.These limit values render it possible to early and safely distinguish anemergency braking from an uncritical ‘usual’ braking action. Favorably,a dependency of the brake pedal speed on the brake pedal travel or thequantity derived therefrom is also considered.

The invention provides that at least one brake pedal application limitvalue is modified according to at least one driver action, especiallythe movement of the driver's foot, before touching the brake pedal. Dueto a modification of the limit value or weighting of the quantityrepresentative of the brake pedal application, it is possible to adaptthe brake assist at a very early point of time to a possibly prevailingemergency braking situation.

It is arranged for in the invention that at least one brake pedalapplication limit value is modified according to at least one detectedaccelerator pedal application, in particular an accelerator pedal returnspeed, an accelerator pedal acceleration, an accelerator pedal jerk, anaccelerator pedal performance and/or an accelerator pedal performancevariation. It has shown that these accelerator pedal applicationsrepresent useful criteria for possible danger situations or emergencybraking situations or a driver's request for maximum deceleration,and/or a critical driving situation.

The brake pedal application limit value is changed according to theinvention when there was detected an accelerator pedal return speedhigher than 20 mm/s, preferably higher than 50 mm/s, an acceleratorpedal acceleration exceeding 500 mm/s², preferably exceeding 1500 mm/s²,an accelerator pedal jerk exceeding 20000 mm/s³, preferably exceeding100000 mm/s³, an accelerator pedal performance exceeding 100000 mm²/s³and/or an accelerator pedal performance variation exceeding 100000000mm²/s⁴. It was found that these limit values provide an early indicationof a possible full braking or emergency braking operation.

It is arranged for in the invention that at least one brake pedalapplication limit value is modified in accordance with a sensed time ofshifting the foot from the accelerator pedal to the brake pedal, afoot-shift acceleration, an acceleration of return of the foot from theaccelerator pedal and/or an acceleration of its approach towards thebrake pedal, with the foot-shift time, foot-shift speed and/orfoot-shift acceleration being preferably detected by an end position ofan electronic accelerator pedal and the commencement of the applicationof the brake pedal. These parameters allow determining anotherindication of an emergency braking or full braking situation.

The brake pedal application limit value is modified according to theinvention when a foot-shift time is shorter than 0.2 s, preferablyshorter than 0.1 s, a foot-shift acceleration exceeds 200 cm/s²,preferably exceeds 800 cm/s², an acceleration of return of the foot fromthe accelerator pedal exceeds 500 cm/s², preferably exceeds 1000cm/s^(2,) and/or an acceleration of the foot's approach towards thebrake pedal exceeds 200 cm/s², preferably exceeds 1000 cm/s². Theselimit values permit relatively detecting a suspected emergency brakingor full braking situation.

The object is also achieved because in a method for implementing anautomatic braking action, wherein at least one quantity representativeof the application of the brake pedal is determined and an automaticbraking action is triggered when at least one limit value (brake pedalapplication limit value) of the quantity representative of theapplication of the brake pedal is exceeded, in particular inhering thepreviously described features of the invention, the braking pressure isincreased in several steps, preferably in three steps, when theautomatic braking action is introduced or executed. The expression‘braking pressure’ has a very broad meaning in this respect. Accordingto the invention, said meaning also covers all derivable quantities suchas brake torque, braking force or vehicle deceleration, which lead to aslowing down of the vehicle due to brake application. The stepwisebraking pressure build-up permits triggering and controlling theautomatic braking action in a way as efficient, yet also comfortable, aspossible.

According to the invention, ‘suspected’ danger situations or emergencybraking situations or a suspected driver's request for maximumdeceleration and/or a critical driving situation are determined on thebasis of at least one driver action, in particular a detected movementof the driver's foot, before an application of the brake pedal of thebraking action considered and/or before the braking action considered.The term ‘suspected danger situations or emergency braking situations ora suspected driver's request for maximum deceleration and/or a criticaldriving situation’ according to the invention implies the likelihood ofdanger situations or emergency braking situations or a driver's requestfor maximum deceleration and/or a critical driving situation.

The braking pressure is increased in several steps in the inventionaccording to the detection probability or detection accuracy of thesuspected danger situations or emergency braking situations or thedriver's request for maximum deceleration and/or the critical drivingsituation. Thus, the assistance given to the driver by the brake assistin conformity to the detection situation prevailing, is conformed to adanger or emergency braking, whereby the comfort and efficiency areincreased.

It is arranged for in the invention that suspected danger situations oremergency braking situations or a driver's request for maximumdeceleration and/or a critical driving situation are determined on thebasis of at least one driver action, preferably the movement of adriver's foot, in particular the ‘braking foot’, prior to touching orapplying the brake pedal. An early adaptation of the driver assistanceis possible by detecting suspected danger situations or emergencybraking situations or a driver's request for maximum deceleration and/ora critical driving situation before the contact or application of thebrake pedal.

The invention provides that suspected danger situations or emergencybraking situations or a driver's request for maximum deceleration and/ora critical driving situation are determined on the basis of a sensedtime of foot-shift from the accelerator pedal to the brake pedal, afoot-shift acceleration, an acceleration of return of the foot from theaccelerator pedal and/or an acceleration of its approach towards thebrake pedal. It has shown that these movements of the driver's footallow detecting the suspicion.

According to the invention, suspected danger situations or emergencybraking situations or a driver's request for maximum deceleration and/ora critical driving situation are determined when a quick return of theaccelerator pedal, preferably an acceleration of return from theaccelerator pedal exceeding 500 cm/s², a quick shift movement of thedriver's foot from the accelerator pedal to the brake pedal, preferablya foot-shift time shorter than 0.1 s or a foot-shift accelerationexceeding 800 cm/s², and/or a relatively quick approach of the driver'sfoot towards the brake pedal, preferably an acceleration of approachtowards the brake pedal exceeding 1000 cm/s² is detected. It has shownthat the suspicion can be reliably detected when these limit values aretaken into consideration.

It is arranged for by the invention that the vehicle brakes arepreconditioned by overcoming the clearances and applying the brake padsto the brake disc and/or drums and, possibly, build-up of a very lowbraking pressure of up to 2 bar approximately, when suspected dangersituations or emergency braking situations or a driver's request frommaximum deceleration and/or a critical driving situation was determined,that the braking pressure is increased to a low pressure value,preferably to a braking pressure of roughly 2 bar to roughly 5 bar whensuspected danger situations or emergency braking situations or thedriver's request for maximum deceleration and/or the critical drivingsituation are continuously detected, and that the braking pressure isincreased to a high pressure value, preferably to a maximum brakingpressure and in particular at a maximum braking pressure build-up speedwhen the suspicion is considered as confirmed and danger situations oremergency braking situations or a driver's request for maximumdeceleration and/or a critical driving situation were detected onaccount of the brake pedal movement or application initiated by thedriver, in particular the brake pedal speed and/or quantities derivedtherefrom. This permits achieving a high degree of ‘braking comfort’ forthe driver and a safe automatic braking of the vehicle in the sense of abrake assist intervention.

Consequently, the above object is achieved by a method for implementingan automatic braking action comprising the following steps:

Detecting and evaluating a situation before application of the brakepedal by the driver,

preconditioning the vehicle brakes, in particular overcoming theclearances and applying the brake pads to the brake disc and/or drumsand, as the case may be, build-up of a very low braking pressure of 1 tomaximally 2 bar, which does not cause any noticeable vehicledeceleration, when an indication or a suspicion of a driver's requestfor a defined deceleration and/or a critical driving situation wasdetected,

continuous detecting and evaluating a situation before application ofthe brake pedal by the driver,

generating a very low braking pressure, preferably 2 -5 barapproximately, which causes a very insignificant, hardly noticeablevehicle deceleration when an indication or a suspicion of a driver'srequest for a defined deceleration and/or a critical driving situationwas continuously detected,

scanning or detecting and evaluating the pedal movement of the brakepedal initiated by the driver, in particular the pedal speed orquantities derived therefrom,

generating the increased braking pressure with preferably maximumbraking pressure increase speed when a driver's request for a maximumdeceleration and/or a critical driving situation was detected on accountof the pedal movement of the brake pedal initiated or executed by thedriver.

The braking pressure build-up for the automatic braking of the vehicleis favorably generated by an active booster or by means of a hydraulicpump. The use of the invention method is especially advantageous in abrake-by-wire brake system, wherein the braking pressure is generated bymeans of auxiliary energy, the brake pedal is coupled to a pedal travelsimulator and the auxiliary energy source is controlled electronicallyin accordance with brake pedal application. In this brake system it istechnically very simply, safely and precisely possible to realize thebrake assist in the sense of the invention by means of a correspondingactuation of the auxiliary energy source or the brake-by-wire brakesystem.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 is a graph depicting the graded automatic application of brakingpressure according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The resultant vehicle deceleration a is plotted against time t in theFigure for a vehicle deceleration F (solid line) that is triggered bythe driver alone, an automatic vehicle deceleration by an ideal brakeassist BA_(id) (line with short dashes), an automatic vehicledeceleration by a brake assist BA_(old) of the state-of-the-art (linewith long dashes) as well as an automatic vehicle deceleration by abrake assist BA_(new) of the invention (dash-and-dot line). The eventthat triggers full braking (critical driving situation) takes place attime t_(0.) After a defined reaction time Δ_(1,) the movement of theaccelerator pedal, that means a return movement of the acceleratorpedal, starts at time t₁. If it were possible to detect the driver'srequest for full braking at this point of time, the braking pressurecould be built up as quickly as possible, after a defined response timeof the brake Δ₂, and the vehicle could be decelerated according to curveBA_(id). The curves of the vehicle deceleration by means of the brakeassist are represented in a schematic and ideal fashion herein and inthe other curves BA_(old), BA_(new).

With the conventional brake assist, it is possible to automaticallyinitiate full braking only commencing at time t₃ starting with which aquick brake pedal application by the driver and the request for amaximum deceleration can be detected. Initially, the response time ofthe brake Δ₃ must still be overcome for braking pressure build-up inorder to displace brake fluid volumes, overcome the clearances, andapply the brake pads to the disc or drum, in particular in hydraulicsystems.

The invention renders it possible to find out the probability that a‘suspicion’ of an emergency braking situation exists commencing at timet₁. Therefore, the clearances can be overcome and so low a brakingpressure may maximally be applied that decelerates the vehicle in a wayunnoticeable to the driver at that time already. However, if startingfrom time t₂ the suspicion of the emergency braking situation iscontinuously detected, that means if an emergency braking situation isfurther likely, a defined pilot pressure, preferably some bar brakingpressure, such as 2 to 10 bar, preferably 2 to 5 bar, in particularroughly 3 bar, will already be built up, whereby the vehicle deceleratesalready noticeably, yet only weakly. It is, however, possible at anytime to discontinue the braking pressure build-up if the suspicionproves wrong, that means if the probability of the emergency brakingsituation reduces again, in that the driver e.g. applies the acceleratorpedal again.

If, on the other hand, there is a still relatively great likelihood ofsubsequent full braking, it is possible to initiate full braking—basedon the already prevailing braking pressure—already at the commencementof the brake pedal movement starting with time t₃ upon application ofthe brake pedal. This feature not only shortens the response time ofbrake Δ₃. Also, a defined vehicle deceleration has already occurred.Admittedly, the even relatively low braking pressure has only arelatively low vehicle deceleration as a result, but it has a majorinfluence on the stopping distance. With a brake system that is‘preconditioned’ this way, the stopping distance can be shortened to arelatively great extent. When the emergency situation for full brakingwas detected correctly, the driver will not assess the minor vehicledeceleration until time t₂ as a loss in comfort. As the method of theinvention, on the other hand, provides a very high rate of safety ofdetecting the emergency situation, a noticeable vehicle deceleration,even if no automatic full braking or strong deceleration followssubsequently, becomes noticeable to the driver only very rarely, thismeans, in tolerable exceptional cases.

The invention will now be explained in detail by way of an embodiment.

To improve the function of the brake assist system, the limit values orswitching thresholds of the brake assist are adapted also with respectto the driver's actions before the contact with the brake pedal inaddition to a dependency on the driving speed and the brake pedaltravel. In particular, the speed limit values (speed thresholds) of thebrake assist are reduced as soon as the driver's actions indicate fullbraking or emergency braking. A quick return of the accelerator pedal, aquick shift of the driver's foot from the accelerator pedal to the brakepedal, and a quick approach of the driver's foot towards the brake pedalare considered as a driver's action indicative of an emergency brakingaction. The modification of the switching thresholds of the brake assistdue to the detected driver action prior to a braking operation is of atemporary nature.

The modification is made smaller as a function of time. To detect thedriver actions indicative of an emergency braking, proximity sensors inthe brake pedal, light barriers or cameras in the leg room and at leastone detection device for the accelerator pedal position can be usedalternatively and in combination. However, there is at least provisionof a sensing device for the non-actuated accelerator pedal position. Itis favorable in terms of costs in vehicles equipped with an electronicaccelerator pedal (E-gas) to use the already provided signal for theaccelerator pedal position as additional information of the brake assistimproved according to the invention. Additional sensors, such as lightbarriers, proximity switches and end position switches are not necessaryin this preferred configuration.

In another embodiment of the brake assist of the invention, brakingoperations are actively triggered before the driver touches the brakepedal. Expecting a subsequent braking operation by the driver, thiscorrespondingly ‘extended’ brake assist can initiate an automaticallytriggered braking action, preferably at an only low braking pressure tobegin with. Subsequent to this action, automatic braking and braking bythe driver can be superimposed upon each other similar to currentpractices employed in the brake assist in the art. As a basic feature,this embodiment provides a graded intensity of the actively(automatically) introduced braking actions, and the grading is variedaccording to an estimated ‘import’ of the expected emergency brakingsituation, this means an expected necessary intensity of deceleration,and the likelihood or detection safety, e.g. by way of a probabilitycoefficient. The grading in dependence on the intensity and detectionsafety is carried out continuously, and the grading is feasibleaccording to the current situation in the direction of a higher brakingpressure or lower braking pressure. The estimated ‘import’ of theexpected emergency braking situation is preferably determined inaccordance with the accelerator pedal speed, the accelerator pedalposition and the speed of the driver's foot at selected measurementpositions in the leg chamber and by way of the speed at which the footlifts from the accelerator pedal, its speed of approach towards thebrake pedal and the time of foot-shift from the accelerator pedal to thebrake pedal. A probability coefficient indicates how probable theexpected emergency braking situation is. The values determined areweighted and assessed in that a detected high speed of approach towardsthe brake pedal results in a higher increase of the probabilitycoefficient than a detected high return speed of the foot from theaccelerator pedal. It applies in general that emergency braking is morelikely to follow events indicative of emergency braking situations to beexpected towards the end of the shift phase of the driver's foot with agreater likelihood than events at the beginning of or prior to the shiftprocess. Therefore, the probability coefficient—beside the type of thedetected events—is also evaluated especially according to the timeperiod, how long the individual events are already ago. For example, aquick return of the accelerator pedal is initially linked to a definedprobability value which decreases with the time in which no furtherevent relevant for an emergency braking action takes place, continuouslyor in steps (what is advantageous for a software program) and becomeszero after lapse of a predetermined interval.

After grading the intensity of the actively initiated braking action, anominal braking pressure is predetermined that is converted into anactual braking pressure by the extended brake assist, e.g. with the aidof an active vacuum brake booster. In an emergency braking situationexpected with only little likelihood, initially a low pressure, e.g. 2bar, is applied to the brakes. This causes the brake pads to move tobear against the friction surfaces of the brakes. The clearance of thebrakes is overcome, with the result that the driver will find apreconditioned brake with minimized lost travels in the subsequent brakeapplication. When the emergency braking is most probable to be expected,the vehicle can be decelerated distinctly already in the shift phase ofthe driver's foot, thereby saving precious meters of stopping distance.

Thus, the invention enhances the efficiency of the brake assist system.It is possible to achieve an early triggering and an improved securityof correctly detecting emergency situations.

1-14. (Canceled)
 15. Method for carrying out an automatic brakingaction, comprising the steps of: determining a quantity representativeof the application of the brake pedal, triggering an automatic brakingaction when at least one limit value of the quantity representative ofthe application of the brake pedal is exceeded, varying the brake pedalapplication limit value or, weighting quantity representative of thebrake pedal application according to an action of the driver prior to anapplication of the brake pedal of the braking action considered or priorto the proper braking action considered.
 16. Method as claimed in claim15, wherein a defined brake pedal force, a brake pedal travel, a brakepedal speed, or a brake pedal acceleration is used as a brake pedalapplication limit value.
 17. Method as claimed in claim 15, wherein anactuating speed of the brake pedal exceeding 50 mm/s is predetermined asa brake pedal speed limit value.
 18. Method as claimed in claim 15,wherein at least one brake pedal application limit value is modifiedaccording to at least one driver action before the driver touches thebrake pedal.
 19. Method as claimed in claim 15, wherein at least onebrake pedal application limit value is modified according to at leastone sensed accelerator pedal application.
 20. Method as claimed in claim15, further comprising the steps of: modifying the brake pedalapplication limit value to at least one sensed accelerator pedalapplication, wherein at least one brake pedal application limit value ischanged when an accelerator pedal return speed higher than 20 mm/s isdetected, an accelerator pedal acceleration exceeding 500 mm/s² isdetected, an accelerator pedal jerk exceeding 20000 mm/s³, anaccelerator pedal performance exceeding 100000 mm²/s³ is detected, or anaccelerator pedal performance variation exceeding 100000000 mm²/s⁴ isdetected.
 21. Method as claimed in claim 15, wherein at least one brakepedal application limit value is modified in accordance with a sensedtime duration taken by the driver to shift the driver's foot from theaccelerator pedal to the brake pedal, a foot-shift acceleration, anacceleration of return of the foot from the accelerator pedal, or anacceleration of the foot's approach towards the brake pedal.
 22. Methodas claimed in claim 15, the method further comprising the step of:modifying one brake pedal application limit value in accordance with asensed time of shifting the foot from the accelerator pedal to the brakepedal, a foot-shift acceleration, an acceleration of return of the footfrom the accelerator pedal, or an acceleration of the foot's approachtowards the brake pedal, wherein at least one brake pedal applicationlimit value is modified when a foot-shift time is shorter than 0.2 s, afoot-shift acceleration exceeds 200 cm/s², an acceleration of return ofthe foot from the accelerator pedal exceeds 500 cm/s², or anacceleration of the foot's approach towards the brake pedal exceeds 200cm/s².
 23. Method as claimed in claim 15, further including the step of:determining a suspected danger situation or emergency braking situationon the basis of a driver action before an application of the brake pedalor before the considered braking action.
 24. Method as claimed in claim15, further including the step of: determining a suspected dangersituation or emergency braking situation on the basis of a driver actionbefore an application of the brake pedal or before the consideredbraking action, wherein the automatic braking action is executed inaccordance with a detection likelihood or detection accuracy of thesuspicion or the danger situations or emergency braking situations. 25.Method as claimed in claim 15, further including the step of:determining a suspected danger situation on the basis of a driver actionbefore an application of the brake pedal or before the consideredbraking action, wherein the automatic braking action is executed inaccordance with a detection likelihood or detection accuracy of thesuspicion or the danger situations or emergency braking situations, andwherein suspected danger situations or emergency braking situations aredetermined on the basis of a sensed time of foot-shift from theaccelerator pedal to the brake pedal, a foot-shift acceleration, anacceleration of return of the foot from the accelerator pedal and/or anacceleration of the foot's approach towards the brake pedal.
 26. Methodas claimed in claim 15, further including step of: determining asuspected danger situations or emergency braking situation on the basisof a driver action before an application of the brake pedal or beforethe considered braking action, wherein the automatic braking action isexecuted in accordance with a detection likelihood or detection accuracyof the suspicion or the danger situations or emergency brakingsituations, and wherein suspected danger situations or emergency brakingsituations are determined on the basis of a sensed time of foot-shiftfrom the accelerator pedal to the brake pedal, a foot-shiftacceleration, an acceleration of return of the foot from the acceleratorpedal or an acceleration of the foot's approach towards the brake pedal,wherein suspected danger situations or emergency braking situations aredetermined when a quick return of the accelerator pedal, a quick shiftmovement of the driver's foot from the accelerator pedal to the brakepedal, and/or a relatively quick approach of the driver's foot towardsthe brake pedal is sensed.
 27. Method as claimed in claim 15, furtherincluding the step of: determining a suspected danger situation oremergency braking situation on the basis of a driver action before anapplication of the brake pedal or before the considered braking action,and wherein the automatic braking action is executed in accordance witha detection likelihood or detection accuracy of the suspicion or thedanger situations or emergency braking situations, wherein the vehiclebrakes are preconditioned by overcoming the clearances and applying thebrake pads to the brake disc and/or drums and, as the case may be,build-up of a very low braking pressure of up to 2 bar approximately,when suspected danger situations or emergency braking situations weredetermined, and wherein the braking pressure is increased to a lowpressure value when suspected danger situations or emergency brakingsituations are continuously detected, and wherein the braking pressureis increased to a high pressure value when the suspicion is consideredas confirmed and danger situations or emergency braking situations areconsidered as detected on account of the brake pedal movement initiatedor executed by the driver.
 28. Method for implementing an automaticbraking action, comprising the steps of: determining quantityrepresentative of the application of the brake pedal, and triggering anautomatic braking action when at least one limit value of a quantityrepresentative of the application is exceeded, wherein the brakepressure is increased in several steps, for executing the automaticbraking action.
 29. Method as claimed in claim 28, further including thestep of: determining a suspected danger situation or an emergencybraking situation on the basis of a driver action before an applicationof the brake pedal or before the considered braking action.
 30. Methodas claimed in claim 28, further including the step of: determining asuspected danger situation or an emergency braking situation on thebasis of a driver action before an application of the brake pedal orbefore the considered braking action, wherein the automatic brakingaction is executed in accordance with a detection likelihood ordetection accuracy of the suspicion or the danger situations oremergency braking situations.
 31. Method as claimed in claim 28, furtherincluding the step of: determining a suspected danger situation or anemergency braking situation on the basis of a driver action before anapplication of the brake pedal or before the considered braking action,wherein the automatic braking action is executed in accordance with adetection likelihood or detection accuracy of the suspicion or thedanger situations or emergency braking situations, wherein suspecteddanger situations or emergency braking situations are determined on thebasis of a sensed time of foot-shift from the accelerator pedal to thebrake pedal, a foot-shift acceleration, an acceleration of return of thefoot from the accelerator pedal and/or an acceleration of the foot'sapproach towards the brake pedal.
 32. Method as claimed in claim 28,further including the step of: determining a suspected danger situationor an emergency braking situations on the basis of a driver actionbefore an application of the brake pedal of or before the consideredbraking action, wherein the automatic braking action is executed inaccordance with a detection likelihood or detection accuracy of thesuspicion or the danger situations or emergency braking situations, andwherein suspected danger situations or emergency braking situations aredetermined on the basis of a sensed time of foot-shift from theaccelerator pedal to the brake pedal, a foot-shift acceleration, anacceleration of return of the foot from the accelerator pedal or anacceleration of the foot's approach towards the brake pedal, whereinsuspected danger situations or emergency braking situations aredetermined when a quick return of the accelerator pedal, a quick shiftmovement of the driver's foot from the accelerator pedal to the brakepedal, or a relatively quick approach of the driver's foot towards thebrake pedal is sensed.
 33. Method as claimed in claim 28, furtherincluding the step of: determining a suspected danger situation or anemergency braking situation on the basis of a driver action before anapplication of the brake pedal of or before the considered brakingaction, wherein the automatic braking action is executed in accordancewith a detection likelihood or detection accuracy of the suspicion orthe danger situations or emergency braking situations, wherein thevehicle brakes are preconditioned by overcoming the clearances andapplying the brake pads to the brake disc or drums and build-up of avery low braking pressure of up to 2 bar approximately, when suspecteddanger situations or emergency braking situations are determined, andwherein the braking pressure is increased to a low pressure value whensuspected danger situations or emergency braking situations arecontinuously detected, and wherein the braking pressure is increased toa high pressure value when the suspicion is considered as confirmed anddanger situations or emergency braking situations are considered asdetected on account of the brake pedal movement initiated or executed bythe driver.
 34. Method for implementing an automatic braking action,wherein at least one quantity representative of the application of thebrake pedal is determined, and an automatic braking action is triggeredwhen at least one limit value (brake pedal application limit value) ofthe quantity representative of the application is exceeded, wherein thebrake pressure is increased in several steps, preferably in three steps,for executing the automatic braking action as claimed in claim 15,wherein the brake pressure is increased in several steps, for executingthe automatic braking action.